Support is requested for a scientific meeting organized by the American Association for Cancer Research, Inc. (AACR). This meeting, to be held at the Banff Springs Hotel from December 7-12, 1992, will focus on the relationships among chemicals, mutations, and cancer. Our goal is to bring together scientists from diverse disciplines who investigate molecular mechanisms causally associated with human cancer. There will be nine formal sessions, each including a Chairperson and three speakers, and during each session time will be set aside for extensive audience discussion. In addition, there will be an introductory session and three poster sessions of preferred papers. The Chairpersons and Speakers are outstanding and imaginative scientists. We anticipate 225 to 250 registrants, many of whom will have the opportunity to discuss their own work during the poster sessions. This conference will present the latest discoveries in the area of chemical carcinogenesis, mutagenesis, and human cancer. The scope of presentations will span topics from the structure of chemical DNA alterations, their mutagenic and carcinogenic potential, their effects on DNA replication and transcription, the mechanisms by which they are repaired in eukaryotic cells, and their effects on genomic stability. The key focus is the application of molecular biology to the study of human cancer. New techniques of molecular biology and synthetic and structural chemistry have had a major impact on the fields of chemical carcinogenesis, mutagenesis, and tumor progression. It is now feasible to synthesize DNA with modifications that are the same as those produced in cells by chemical carcinogens and to determine the three-dimensional structure of the modified DNAs. One can now introduce chemically modified nucleotides into biologically active DNA molecules at predetermined positions and then determine the frequency and types of mutations caused by these alterations in DNA. Further, genes whose products modulate mutation induction, because they act on damaged DNA or maintain replication fidelity, have been identified and cloned, and their role in carcinogenesis can now be assessed. Parallel efforts have resulted in the identification and characterization at the DNA sequence level of a number of genes, including oncogenes and suppressor genes, apparently involved in human cancer. Participants in the conference will be drawn from each of the scientific areas represented in the Conference. We are confident that the exchange of ideas among scientists in these fields will stimulate new and original ideas that will contribute to progress in cancer research.